The spectacle frames, without the pads, without lenses and without the ear sleeves, are polished smooth for a few hours in polishing drums. In this finished state, the end regions of the spectacle yokes are still straight, i.e. not bent corresponding to the later ear shape.
The spectacle frames are held, according to a prior art process, in such a support of respectively 9 pieces. The support consists of a box profile, which has respective arms to right and left. Each arm merges at its end into a ring, which has a diameter in the centimeter range. The end regions of the spectacle yokes are located within these rings. At the upper side are provided ten punch pins which likewise carry a ring at their ends, which however is substantially smaller than the previously mentioned ring. A plastics loop is slipped through these rings and is held festoon-like by the rings. The low point of each festoon acts as a support for the interior side of the bridge of the spectacle frame.
So that the spectacle frames do not float away in the polishing medium, a fixing bar is also put through the smaller rings above the bridges; it is as long as the box profile. So that this securing bar does not itself float away, it is secured. This construction has the following disadvantages:
(a) The flow resistance which this support exerts on the polishing medium is relatively high. PA1 (b) Only a completely determined number of spectacle frames can be polished, quite independently of whether they are large or small. PA1 (c) The bridge of the spectacle frame is indeed held on one side by the plastics loop and on the other side by the securing pin. The bridge is therefore always insufficiently processed and frequently even scratched, because polishing medium particles penetrate between the bridge and the securing rod and/or the plastics loop. This leads to reprocessing. PA1 (d) The plastics loop must be frequently changed, because the polishing medium abrades the plastics. Apart from this, those rings which hold the end regions of the spectacle frame yoke, are clad with a plastics sheathing. Even this is abraded and must be frequently changed. PA1 (e) Every polishing is associated with vibrations. The screws of the closing blocks therefore often loosen during use of the known support. If the screws have fallen out, the lens edge can be bent, since in fact the polishing medium flows onto it from below. It is conjectured that the lens edge screws open because the vibrations of polishing lead to knee-like movements of the lens edge. PA1 (f) The production of the support is expensive. PA1 (a) The crossbar device comprises two crossbars which run mutually parallel and are spaced apart at a distance corresponding to the spacing of the end regions of the spectacle yokes, and their end regions are rigidly connected together by crossyokes. PA1 (b) Each crossbar comprises two adjacent, flexurally stiff partial bars, a respective partial bar being able to be clamped against the neighboring one by clamping means, in the manner of a vise. PA1 (c) The partial bars have at most a clamping height which corresponds to the unprocessed length of the spectacle yoke end regions.